Antenatal Screening Flashcards
(53 cards)
What is screening?
Screening is the process of identifying apparently healthy people who may have an increased chance of a disease or condition.
What do the UK national screening committee do?
Advises the govt on introducing and amending screening programmes
What do the Dept of Health and Social Care do?
Sets health screening policy for England and provides funding and holds other health bodies to account for their performance
What do NHS England do?
Commissions screening services
Implements agreed changed to screening programmes
What is the criteria for a screening programme?
The condition - important health problem
Test- simple, safe, precise - acceptable to target population
Intervention - effective intervention with evidence of better outcomes
Screening programme - evidence from RCT’s that programme is effecting in reducinging morbidity and mortality
Implementation criteria -
What are some antenatal and newborn screening?
Sickle cell and Thalassemia
Infectious diseases screening
Down’s Edwards’ and Patau’s syndrome screening
Fetal anomaly scan
Diabetic eye screening
Newborn infant physical examination
Newborn hearing screen
Newborn blood spot
What are the key objectives of Screening?
Identify the eligible population
Provide information
Explain the conditions, purpose of screening, the test, limitations, results pathways, treatment options
Document the decision to accept/decline
Perform the test
Communicate the results and document in notes/maternity system
Ensure timely transition into appropriate follow-up and treatment for those that screen positive
Optimise health outcomes
What is the aim of offering screening?
The aim is to offer screening to the people who are most likely to benefit from it.
The eligible cohort will be different for each programme.
Pathway including numerous health and allied professionals has the potential for errors in screening if key steps are missed.
What is the overview of haemoglobinopathies? (Sickle cell and thalassaemia)
Haemoglobinopathies > 1.Genes affect quality and structure of haemoglobin + 2. Genes affect quantity of haemoglobin > 1. Haemoglobin variants (HbS, HbO, HbE) + 2. Thalassaemia such as alpha or beta
What inheritance are haemoglobin disorders
Recessive
What is an overview of sickle cell disease
Affect haemoglobin - RBC is sickle shaped
Main symptoms - anaemia + severe pain (sickle cell crisis)
Risk of stroke, ACS, blindness, bone damage, chronic organ damage, death
Cure= bone marrow transplant
Coloured people disease
How does pain occur in sickle cell disease?
Pain occurs when the cells change shape when the oxygen is released causing blockages in capillaries – treated with strong pain killers or Hydroxyurea to reduce frequency
Overview of B Thalassaemia
β found in people originating from Mediterranean, Middle East, Africa or Asia may carry some form of thalassaemia
β thalassaemias are a group of hereditary disorders that result in reduced or absent synthesis of β globin chains
β thalassaemia major patients require lifelong transfusion therapy and chelation therapy to treat complications of resulting iron overload
Overview of A Thalassaemia
α zero thalassaemia is most commonly found in those of Southeast Asian origin and East Mediterranean and in low frequencies in some Middle Eastern countries
α thalassaemia major invariably fatal without treatment resulting in hydrops fetalis due to severe fetal anaemia
The mother is at risk of obstetric complications, such as pre-eclampsia, particularly in the third trimester of pregnancy
What is a major problem in alpha thalassaemia?
The lack of a specific biomarker for the detection of α thalassaemia carriers creates problems, particularly in the context of a screening programme. In this context α+ thalassaemia is not regarded as significant and policies are designed to detect only couples at risk of hydrops fetalis.
What is the Sickle cell and thalassaemia screening pathway>
- Offered to all pregnant women ideally by 8-10 weeks, biological father of the baby if mother is a genetic carrier, un-booked women in labour
- High prevalence Trust – universal screening
- Family Origin Questionnaire accompanies the blood sample and assists laboratory to interpret results and request appropriate testing
- Egg donor pregnancy – need to test biological father
- Egg donor and sperm donor – potentially at risk pregnancy unless donors tested by fertility centre and status known
- If the woman and biological father are identified/known to be carriers – offered counselling and prenatal diagnosis by 12+0 weeks
- Prenatal diagnosis by 12+6 and results within 5 days
- Can be offered termination of pregnancy for an affected fetus
What are family origin questionnaires used for?
Family origin questionnaire (FOQ) used to assist laboratories to interpret results. The requester indicates the family origins of both the mother and the biological father of the baby.
What is the process for infectious disease screening?
- Screening for HIV, Hepatitis B and Syphilis offered and recommended to all women in early pregnancy and unbooked women in labour
- Early detection and treatment to reduce mother to child transmission
- Re-offered by 20 weeks by the screening team to any woman who initially declines
- Positive/known positive women are contacted and informed by the screening team within 10 days of the result
- Cared for by a defined MDT for appropriate specialist care
What should all babies born to mothers with an infectious disease have ?
MDT plan of care and/or neonatal alert process in place for babies requiring assessment and treatment at birth in line with clinical guidance from the professional bodies
Babies born to mothers with Hepatitis B should be vaccinated within 24 hours of birth and at 4, 8, 12 and 16 weeks then at 12 months
Syphilis overview
Caused by the bacteria-like spirochete Treponema Pallidum transmitted primarily through sexual contact with an infectious lesion (chancre)
Can be transmitted transplacentally at any stage in pregnancy and may result in miscarriage, pre-term labour, stillbirth and congenital syphilis.
HIV overview
Human immunodeficiency virus (HIV) is a retro-virus which leads to immunosuppression and eventually to acquired immune deficiency syndrome (AIDS) if left untreated.
Present in all body fluids passed on through sexual intercourse, direct contact with blood of an infected person, sharing needles and mother to child in pregnancy
Hep B overview
An infectious inflammatory illness of the liver caused by the hepatitis B virus (HBV)
Very infectious, present in all bodily fluids and transmitted in the same way as HIV
What does Hep B mean for the baby?
- Mother to child transmission dependent on phase of maternal infection and her level of infectivity
- Higher infectivity p 70-90% vertical transmission risk without intervention
- Lower infectivity - 10% risk vertical transmission without intervention
- Chronic infection occurs in 90% of babies infected perinatally
Screening for Down’s (T21), Edwards (T18) and Patau (T13) ?
- Testing for T21/T18/T13 offered to all pregnant women
- Combined test recommended 11+2–14+1 weeks
- Quadruple testing for Down’s syndrome offered 14+2 – 20+0 if NT not possible after 2 attempts or too late
- The screening strategy for T18/T13 after quadruple testing is the 18+0 – 20+6 scan
Combined and quadruple offered in twin pregnancies - Low chance results by letter
- Higher chance results by screening and offer of PND
- Close pathway by documenting results or checking has declined and documenting decline
